Combination and key operated locks have been previously provided in the art and may be employed in a variety of situations to secure enclosed areas or containers. Non-limiting examples may include lockers, rooms, lock boxes, desk drawers, electrical panels, and other similar enclosures. Such locks are convenient from the standpoint that access may be had to a secured item or area by either entering a combination such as by way of manually rotating combination setting elements associated with the lock or by inserting a key into the lock.
Prior United States patents include reference to prior combination and key operated locks. For example, U.S. Pat. No. 6,539,761 to Yang is entitled “Padlock by combining key-operated lock and combination lock” and relates to a padlock which includes a lock body; a shackle operatively locked in or unlocked from the lock body; a key-operated locking device formed in the lock body for operatively unlocking the shackle for unlocking the padlock by using a key, and a combination locking device juxtapositionally formed in the lock body for operatively unlocking the shackle for unlocking the padlock merely by dialing the combination to an unlocking number. U.S. Pat. No. 6,708,534 to Ruan is entitled “Padlock” and relates to a padlock that comprises a shackle, a lock body, a lock cylinder assembly disposed at the middle portion in the lock body, and a combination lock assembly. Such padlock can be operated by either the key or the cipher. Also provided is a padlock having an interchangeable lock cylinder assembly.
Another prior patent is U.S. Pat. No. 6,792,778 by Chen, entitled “Combination lock” and relates to a combination lock comprising a tumbler wheel assembly, a backup locking assembly comprising a keyhole, a shaft, and an inner projection having a half circular section, a pivot assembly having a dog and an engagement member, a push button secured to the pivot assembly, a U-shaped shackle pivotably fastened at the lock housing, and an L-shaped resilient member. A correct combination of tumblers and a subsequent pressing of the push button will disengage the dog from a slot at one leg of the shackle and thus exert an elastic force of the resilient member on the leg for pushing the leg out of engagement with the lock. Should either the combination be forgotten or the combination be changed by another person, a turning of the shaft about 90 degrees by inserting a key into the keyhole will turn the projection and the engaged engagement member for releasing the dog.
U.S. Pat. No. 6,997,023 to Huang is entitled “Combined combination lock and padlock” and relates to a combined combination lock and padlock comprising a second shackle receiving hole including an inside slot at one leg of a shackle of steel rope for receiving a spring depressible block, a tumbler wheel assembly, a key turning assembly, a pivot assembly, a push button, and a U-shaped shackle. A correct combination of tumblers and a subsequent pressing of the push button will disengage a dog with the slot and thus expansion of the block will push the leg out of engagement with the lock. As also stated in U.S. Pat. No. 6,792,778 by Chen, should either the combination be forgotten or the combination be changed by another person, a turning of the shaft about 90 degrees by inserting a key into the keyhole will turn the projection and the engaged engagement member for releasing the dog.
U.S. Pat. No. 7,104,092 to Yu is entitled “Security lock with dual locking means” and concerns a security lock that can be unlocked by the owner of the security lock by dialing an unlocking number or by authorized security personals with a general key. The security lock mainly contains: a lock body, a plugging device, a controlling device, a securing mechanism, a restriction device, a first locking device and a second locking means. The lock body has a first channel and a second channel therein. The plugging device is pluggable into the first channel. The controlling device is slidably secured within the second channel. The securing mechanism is for securing or releasing the plugging device. The restriction device is slidably deposed within the second channel against the controlling device for controlling movement thereof. The first locking device is formed in the lock body for being engaged with or disengaged from the restriction device. The second locking device is formed in the lock body for rotating the restriction device to be disengaged from the first locking device.
U.S. Pat. No. 7,121,123, also to Yu, is entitled “Padlock” and concerns a padlock which comprises a lock body, a shackle, a combination locking device and a key locking device. The shackle is movable relative to the lock body between a locked position and an unlocked position. The combination and key locking devices are installed within the lock body respectively for controlling movements of the shackle. Additionally, the combination locking device has a frame for receiving a first end of the shackle and a combination unit connected to the frame, which is movable when the combination unit is unlock whereby a second end of the shackle is movable to the unlock position. Furthermore, the key locking device comprises a block unit for locking the first end of the shackle and a key unit connected to the block unit, which is movable when the key unit is unlocked by a key.
Depending on the particular use to which the foregoing general types of locks may be applied, it may be convenient or necessary to be able to change the combination for the lock.
In an exemplary known lock structure 100 as illustrated in present FIGS. 1 and 2, desired access may be had by either inserting a key into the lock or by entering a combination (such as by way of manually rotating combination setting elements). In order to change the combination in the exemplary known combination and key operated locks as illustrated herein in FIGS. 1 and 2, the currently configured combination must be used to unlock the assembly, with the combination thereafter changed. If the combination is known, the combination may be changed by use of a set screw 110 (FIG. 1) that may be rotated 90° to engage an actuator 112 (FIG. 2) to place the lock in a combination change mode. The combination cannot be changed with possession of a physical unlocking key. Set screw 110 is independent of a dead bolt mechanism that locks the panel cylinder 106 against the cam lock housing as well as independent of the keyplug 104. In this known arrangement, if the combination is not known and a user tries to change the combination using set screw 110, set screw 110 will partially rotate but will not allow the combination to be changed. In normal lock operation, the combination may be entered manually and the lock opened by actuation of button 102.
In light of these recognized deficiencies, there exists a need for a manual combination and key lock operated lock that provides an improved mechanism for resetting the manual combination.
While various implementations of combination and key operated locks have been developed, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the present subject matter.